Turbomachine seal assembly and method of sealing a rotor region of a turbomachine

ABSTRACT

A turbomachine seal assembly includes a rotor disposed about an axial centerline, the rotor having an outer surface. Also included is a stationary component extending circumferentially about the rotor. Further included is at least one primary annular seal ring operably coupled to the stationary component and extending radially inwardly to close proximity with the outer surface of the rotor. Yet further included is a secondary annular seal ring operably coupled to the stationary component and integrally formed with the at least one primary annular seal ring, the secondary annular seal ring extending radially inwardly to close proximity with the outer surface of the rotor.

BACKGROUND OF THE INVENTION

The subject matter disclosed herein relates to turbomachines, and more particularly to turbomachine seal assemblies, as well as a method of sealing a rotor region.

Dynamic sealing between a rotor (e.g., rotating shaft) and a stator (e.g., static shell or casing) is an important concern in turbomachinery. Numerous sealing approaches have been employed and typically include a primary seal structure that is prone to wearing and potentially failure. Secondary seal structures may be included to account for potential failure of the primary seal structure, but significant spatial requirements for the secondary seal structures often negatively constrain rotor design architecture. Large axial and/or radial spaces may be required to properly accommodate the secondary seal structure.

BRIEF DESCRIPTION OF THE INVENTION

According to one aspect of the invention, a turbomachine seal assembly includes a rotor disposed about an axial centerline, the rotor having an outer surface. Also included is a stationary component extending circumferentially about the rotor. Further included is at least one primary annular seal ring operably coupled to the stationary component and extending radially inwardly to close proximity with the outer surface of the rotor. Yet further included is a secondary annular seal ring operably coupled to the stationary component and integrally formed with the at least one primary annular seal ring, the secondary annular seal ring extending radially inwardly to close proximity with the outer surface of the rotor.

According to another aspect of the invention, a method of sealing a rotor region of a turbomachine is provided. The method includes integrally forming a primary annular seal ring and a secondary annular seal ring. Also included is operably coupling the primary annular seal ring and the secondary annular seal ring to a stationary component extending circumferentially about a rotor, wherein the primary annular seal ring and the secondary annular seal ring extend radially inwardly to close proximity with an outer surface of the rotor.

These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter, which is regarded as the invention, is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a schematic view of a turbomachine;

FIG. 2 is a perspective view of a seal assembly of the turbomachine;

FIG. 3 is a partial cross-sectional view of the seal assembly;

FIG. 4 is a cross-sectional view of the seal assembly according to a first embodiment of a secondary seal;

FIG. 5 is a cross-sectional view of the seal assembly according to a second embodiment of the secondary seal;

FIG. 6 is a cross-sectional view of the seal assembly according to another exemplary embodiment; and

FIG. 7 is a flow diagram illustrating a method of sealing a rotor region of the turbomachine.

The detailed description explains embodiments of the invention, together with advantages and features, by way of example with reference to the drawings.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1, a turbomachine, such as a turbine system, is schematically illustrated with reference numeral 10. The turbine system 10, in the case of a gas turbine engine, includes a compressor 12, a combustor 14, a turbine 16, a rotor 18 and a fuel nozzle 20. It is to be appreciated that one embodiment of the turbine system 10 may include a plurality of compressors 12, combustors 14, turbines 16, rotors 18 and fuel nozzles 20. The compressor 12 and the turbine 16 are coupled by the rotor 18. The rotor 18 may be a single rotor or a plurality of rotor segments coupled together to form the rotor 18. The combustor 14 uses a combustible liquid and/or gas fuel, such as natural gas or a hydrogen rich synthetic gas, to run the turbine system 10. For example, fuel nozzles 20 are in fluid communication with an air supply and a fuel supply 22. The fuel nozzles 20 create an air-fuel mixture, and discharge the air-fuel mixture into the combustor 14, thereby causing a combustion that creates a hot pressurized exhaust gas. The combustor 14 directs the hot pressurized gas through a transition piece into a turbine nozzle (or “stage one nozzle”), and other stages of buckets and nozzles causing rotation of the turbine 16 within a turbine casing 24. Rotation of the turbine 16 causes the rotor 18 to rotate, thereby compressing the air as it flows into the compressor 12.

Although illustrated and described above as a gas turbine engine, an alternative embodiment of the turbine system 10 comprises a steam turbine engine. Also, the embodiments described below may be employed with any turbomachine having a rotor region benefitting from sealing thereabout.

Referring now to FIGS. 2 and 3, an exemplary embodiment of a seal assembly 30 of the turbine system 10 is illustrated. The seal assembly 30 illustrated may be referred to as a compliant plate seal arrangement, but it is to be appreciated that the seal assembly 30 may be in the form of a variety of sealing arrangements, including a foil seal (FIG. 6), for example. Irrespective of the precise seal arrangement, the seal assembly 30 is disposed proximate an outer surface 32 of the rotor 18 for sealing therealong, primarily in an axial direction.

In the exemplary embodiment, the seal assembly 30 reduces axial leakage between the rotor 18 and a stationary component 34. A housing 36 is coupled to the stationary component 34, such that the rotor 18 rotates relative to the housing 36 about an axial centerline. The housing 36 may be coupled to the stationary component 34 in a number of ways, and in the illustrated embodiment the housing 36 is disposed within an annular cavity 40 of the stationary component 34 that may be characterized as having a T-shaped geometry. At least one biasing member 42 is disposed between the housing 36 and the stationary component 34 to bias the seal assembly 30 away from the rotor 18. The at least one biasing member 42 may be a coil spring, a leaf spring or any other biasing mechanism that enables the seal assembly 30 to function as described herein.

The housing 36 includes a primary seal system comprising a primary annular seal ring 50 and a plurality of plate members 52, both extending radially inwardly from the housing 36 and stationary component 34 toward the outer surface 32 of the rotor 18. As illustrated, it is to be appreciated that a plurality of primary annular seal rings may be integrally formed with or operably coupled to the housing 36. The primary annular seal ring 50 is situated at least partially within the plurality of plate members 52. Specifically, each of the plurality of plate members 52 includes a slot 54 in which the primary annular seal ring 50 is disposed within. Each of the plurality of plate members 52 is operably coupled to the housing 36 at a root end 55 and is substantially planar is geometry. The plurality of plate members 52 are spaced circumferentially around the rotor 18, thereby forming a gap 56 between each of the plurality of plate members 52. The primary annular seal ring 50 extending through the slot 54 reduces axial leakage flow between the gap 56.

The seal assembly 30 also includes a secondary annular seal ring 60 that is integrally formed with the primary annular seal ring 50. The secondary annular seal ring 60 is also integrally formed with or is operably coupled to the housing 36, extending radially inwardly therefrom. The secondary annular seal ring 60 is a robust, durable plate that provides a sealing redundancy in the event the primary annular seal ring 50 is rendered ineffective. The secondary annular seal ring 60 may be formed of any material suitable for withstanding system operating temperatures.

Although illustrated and described above as a configuration having the plurality of plate members 52, the primary annular seal ring 50 and the secondary annular seal ring 60 connected to the housing 36, it is to be appreciated that one or all of these components may be integrally formed with, or operably coupled to, the stationary component 34. In one embodiment, the housing 36 is not present.

Referring now to FIGS. 4 and 5, irrespective of whether the plurality of plate members 52, the primary annular seal ring 50 and the secondary annular seal ring 60 are connected to the housing 36 or the stationary component 34, it can be seen that the secondary annular seal ring 60 extends radially inwardly to close proximity with the outer surface 32 of the rotor 18. Specifically, the primary annular seal ring 50 extends to a first radial location 62 and the second annular seal ring 60 extends to a second radial location 64. It is to be appreciated that the second radial location 64 may be closer to the outer surface 32 of the rotor 18 or alternatively may be substantially at a similar radial location to that of the first radial location 62, such that the first radial location 62 and the second radial location 64 are substantially equally spaced from the outer surface 32 of the rotor 18. The secondary annular seal ring 60 is illustrated as being disposed at a location axially forward of the primary annular seal ring 50, however, it is to be appreciated that the secondary annular seal ring 60 may be disposed at a location axially rearward of the primary annular seal ring 50. In another embodiment, a plurality of secondary annular seal rings are present, with at least one of the plurality of secondary annular seal rings disposed axially forwardly of the primary annular seal ring 50 and at least one of the plurality of secondary seal rings disposed axially rearward of the primary annular seal ring 50.

The secondary annular seal ring 60 includes a first end 68 and a second end 70, with the first end 68 in close proximity to the stationary component 34. As described in detail above, the first end 68 may be coupled to, or integrally formed with, the housing 36 or the stationary component 34, but in either event is integrally formed with the primary annular seal ring 50. The second end 70 is disposed in close proximity to the outer surface 32 of the rotor 18. In one embodiment (FIG. 4), the second end 70 includes a toothed segment 72 to provide a desirable aerodynamic profile. In another embodiment (FIG. 5), the second end 70 includes a plurality of teeth segments 74.

As illustrated in the flow diagram of FIG. 7, and with reference to FIGS. 1-6, a method of sealing a rotor region of a turbomachine 100 is also provided. The turbomachine, such as a turbine system 10, and more specifically the seal assembly 30 have been previously described and specific structural components need not be described in further detail. The method of sealing a rotor region of a turbomachine 100 includes integrally forming a primary annular seal ring and a secondary annular seal ring 102. The primary annular seal ring and the secondary annular seal ring are operably coupled to a stationary component extending circumferentially about a rotor 104.

While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims. 

1. A turbomachine seal assembly comprising: a rotor disposed about an axial centerline, the rotor having an outer surface; a stationary component extending circumferentially about the rotor; at least one primary annular seal ring operably coupled to the stationary component and extending radially inwardly to close proximity with the outer surface of the rotor; and a secondary annular seal ring operably coupled to the stationary component and integrally formed with the at least one primary annular seal ring, the secondary annular seal ring extending radially inwardly to close proximity with the outer surface of the rotor.
 2. The turbomachine seal assembly of claim 1, wherein the at least one primary annular seal ring extends to a first radial location and the secondary annular seal ring extends to a second radial location.
 3. The turbomachine seal assembly of claim 2, wherein the second radial location is closer to the outer surface of the rotor.
 4. The turbomachine seal assembly of claim 2, wherein the first radial location and the second radial location are spaced relatively equally from the outer surface of the rotor.
 5. The turbomachine seal assembly of claim 1, wherein the secondary annular seal ring is disposed at an axially forward location relative to the at least one primary annular seal ring.
 6. The turbomachine seal assembly of claim 1, wherein the secondary annular seal ring is disposed at an axially rearward location relative to the at least one primary annular seal ring.
 7. The turbomachine seal assembly of claim 1, further comprising a plurality of secondary annular seal rings, wherein at least one of the plurality of secondary annular seal rings is disposed at an axially forward location relative to the at least one primary annular seal ring, wherein at least one of the plurality of secondary annular seal rings is disposed at an axially rearward location relative to the at least one primary annular seal ring.
 8. The turbomachine seal assembly of claim 1, wherein the secondary annular seal ring comprises a first end and a second end, wherein the first end is disposed in close proximity with the stationary component and the second end is disposed in close proximity to the outer surface of the rotor.
 9. The turbomachine seal assembly of claim 8, wherein the second end of the secondary annular seal ring comprises a toothed geometry.
 10. The turbomachine seal assembly of claim 8, wherein the second end of the secondary annular seal ring comprises a plurality of teeth segments.
 11. The turbomachine seal assembly of claim 1, wherein the at least one primary annular seal ring is disposed at least partially within a slot of a plate member operably coupled to the stationary component.
 12. The turbomachine seal assembly of claim 1, further comprising a housing operably coupled to the stationary component, wherein at least one of the at least one primary annular seal ring and the secondary annular seal ring are integrally formed with the housing.
 13. The turbomachine seal assembly of claim 1, further comprising a housing operably coupled to the stationary component, wherein at least one of the at least one primary annular seal ring and the secondary annular seal ring are operably coupled to the housing.
 14. The turbomachine seal assembly of claim 1, further comprising a housing biasedly supported by a spring disposed between the housing and the stationary component.
 15. A method of sealing a rotor region of a turbomachine comprising: integrally forming a primary annular seal ring and a secondary annular seal ring; and operably coupling the primary annular seal ring and the secondary annular seal ring to a stationary component extending circumferentially about a rotor, wherein the primary annular seal ring and the secondary annular seal ring extend radially inwardly to close proximity with an outer surface of the rotor.
 16. The method of claim 15, further comprising disposing the secondary annular seal ring at an axially forward location relative to the primary annular seal ring.
 17. The method of claim 15, further comprising disposing the secondary annular seal ring at an axially rearward location relative to the primary annular seal ring.
 18. The method of claim 15, further comprising integrally forming a plurality of secondary annular seal rings with the primary annular seal ring and disposing at least one of the plurality of secondary annular seal rings at an axially forward location relative to the primary annular seal ring and at least one of the plurality of secondary annular seal rings at an axially rearward location relative to the primary annular seal ring.
 19. The method of claim 15, further comprising operably coupling the primary annular seal ring and the secondary annular seal ring to a housing operably coupled to the stationary component.
 20. The method of claim 15, further comprising: operably coupling a plate member to the stationary component, disposing the primary annular seal ring within a slot of the plate member; and extending the secondary annular seal ring to a seal radial location at least as close in proximity to the outer surface of the rotor as a plate member radial location. 